Related to explosive bulk charges, it is typically desirable to increase the penetration and/or through-hole diameter when detonated in contact with a wall, armor, or other structure or material. Likewise, it is typically desirable to increase the velocity of an EFP coupled to or otherwise formed by the explosive bulk charges, such as from an attached plate, precut wall, armor, or other structure or material. In the later case, it is also typically desirable to increase the diameter of the EFP coupled to or formed by the explosive bulk charge.
Conventionally, explosive bulk charges used for breaching and/or EFP formation have had either a square or rectangular contact surface, with right angles, or a random geometry of known mass. In each case, the resulting through-hole is substantially circular. An EFP may be formed by such explosive bulk charges by coupling a plate or the like to them, or by precutting a wall, armor, or other structure or material adjacent to them.
For example, U.S. Pat. No. 3,280,743 deals with the directional control of an explosion and provides:                an explosive is confined within a [block] shaped mass having a predetermined shaped surface and detonating means is operatively disposed within said mass to define a selected point of initiation from which gaseous energy upon detonation expands in spherical propagating lines of force that pierce the surface and produce a reactionary force for momentarily enveloping and restraining the energy. The reactionary force is greatest at those places on the surface which conform to the spherical propagating lines of force. With such an arrangement, the confined energy will penetrate the reactionary force at its most vulnerable point and will be released therethrough.        
Likewise, U.S. Pat. No. 5,323,681 deals with the molding of an explosive and provides:                [i]t is the primary object of the invention to shape an explosive charge of an EFP in dimensions that improve slug formation, slug cohesion, and flight characteristics thus optimizing the explosive energy that can be directed into an EFP. It is yet another object of this invention to provide a way to apply the requisite amount of explosive to an EFP without the use of scales to weigh the explosive. It is an object of this invention to provide a means to easily extract the explosive charge from the mold after it has been formed. The present invention meets the above mentioned needs using a shaping apparatus comprising a nonmetal mold, formed into a frustum of a cone, with dimensions having a wide base equaling about 18 inches, a narrow base equaling about 3 inches, and a height equaling about 4 inches. The plastic explosive is hand-packed into the mold so that the explosive takes on the frusto-conical shape of the mold. A latch and a hinge are attached to the mold for easy and quick release of the molded explosive charge.        
Likewise, U.S. Pat. No. 5,540,156 deals with a technique for producing a selectable effects EFP having the ability to defeat either single armored targets or a multiplicity of lightly armored targets and provides:                [a]n object of the present invention is to provide a mechanical method for an explosively formed penetrator (EFP) which utilizes two or more rod networks mounted in an overlapping pattern to allow production of more than one controlled fragment size. Another object of the present invention is to provide a rod array for an EFP which allows production of a multiplicity of fragment sizes. Another object of the present invention is to provide a mechanical selection device for an EFP that is simple to manufacture, inexpensive and adaptable to almost any warhead design. A further object of the present invention is to provide an EFP system that is effective against armored targets, such as tanks, armored personnel carriers and light armored targets such as trucks, missile launchers, and communication stations.        
Likewise, U.S. Pat. No. 5,859,383 deals with shaped charges that may be used as perforators in the mining and petroleum industries, for example, and provides:                [t]hese shaped charges may be used as a well perforation system using energetic, electrically-activated reactive blends in place of high explosives. The reactive blends are highly impact inert and relatively thermally inert until activated. The proposed system requires no conventional explosives and it is environmentally benign. The system and its components can be shipped and transported easily with little concern for premature explosion. It also needs no special handling or packing. The performance in oil and gas well perforation can be expected to exceed that of conventional explosive techniques. The fundamental approach of the present invention is to activate reactive blends of metals and oxidizing agents with energetic electrical pulses from a pulsed-power system. Theoretical predictions of pressures and expansion histories can be verified by testing reactive samples activated with energetic electrical pulses. The energy source of choice is a conductive material which can be burst (e.g., melted and vaporized by pulsed electrical current). Of particular interest are conductive materials such as graphite, conductive polymers and metal such as aluminum, zirconium, copper, titanium, lithium, silver, magnesium, beryllium, manganese, tin, iron, nickel, zinc, boron, silicon and the like in an oxidizing environment, or an environment which becomes oxidizing during the pulsing, bursting and subsequent reaction initiation. It is also desirable to have a power source and conductive path to the reaction mixture that will remain effective in the difficult temperature, stress, and shock environment in which the unit will be employed.        
However, a significant amount of explosive energy is wasted by conventional explosive bulk charges. For this reason, improved explosive bulk charges are still needed in the art.